﻿<!DOCTYPE html>
<html>
<head>
  <title>Overview Resizing</title>
  <!-- Copyright 1998-2020 by Northwoods Software Corporation. -->
  <meta name="description" content="The OverviewResizingTool extension allows the user to change the viewport of the observed Diagram by resizing the box representing the viewport in an Overview." />
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <script src="../release/go.js"></script>
  <script src="../assets/js/goSamples.js"></script> <!-- this is only for the GoJS Samples framework -->
  <script src="OverviewResizingTool.js"></script>
  <script id="code">
    function init() {
      if (window.goSamples) window.goSamples();  // init for these samples -- you don't need to call this

      var $ = go.GraphObject.make;  // for conciseness in defining templates

      myDiagram = $(go.Diagram, 'myDiagramDiv',  // create a Diagram for the DIV HTML element
        {
          layout: $(go.ForceDirectedLayout),
          'undoManager.isEnabled': true  // enable undo & redo
        });

      // Define the Node template.
      // This uses a Spot Panel to position a button relative
      // to the ellipse surrounding the text.
      myDiagram.nodeTemplate =
        $(go.Node, "Spot",
          {
            selectionObjectName: "PANEL",
            isTreeExpanded: false,
            isTreeLeaf: false
          },
          // the node's outer shape, which will surround the text
          $(go.Panel, "Auto",
            { name: "PANEL" },
            $(go.Shape, "Circle",
              { fill: "#03A9F4", stroke: "black" }
            ),
            $(go.TextBlock,
              { font: "12pt sans-serif", margin: 5 },
              new go.Binding("text", "key"))
          ),
          // the expand/collapse button, at the top-right corner
          $("TreeExpanderButton",
            {
              name: 'TREEBUTTON',
              width: 20, height: 20,
              alignment: go.Spot.TopRight,
              alignmentFocus: go.Spot.Center,
              // customize the expander behavior to
              // create children if the node has never been expanded
              click: function(e, obj) {  // OBJ is the Button
                var node = obj.part;  // get the Node containing this Button
                if (node === null) return;
                e.handled = true;
                expandNode(node);
              }
            }
          )  // end TreeExpanderButton
        );  // end Node

      // create the model with a root node data
      myDiagram.model = new go.TreeModel([
        { key: 0, everExpanded: false }
      ]);

      // Overview
      myOverview =
        $(go.Overview, 'myOverviewDiv',  // the HTML DIV element for the Overview
          {
            observed: myDiagram,
            contentAlignment: go.Spot.Center,
            'box.resizable': true,
            'resizingTool': new OverviewResizingTool()
          });

      document.getElementById('zoomToFit').addEventListener('click', function() {
        myDiagram.zoomToFit();
      });

      document.getElementById('expandAtRandom').addEventListener('click', function() {
        expandAtRandom();
      });
    }

    function expandNode(node) {
      var diagram = node.diagram;
      diagram.startTransaction("CollapseExpandTree");
      // this behavior is specific to this incrementalTree sample:
      var data = node.data;
      if (!data.everExpanded) {
        // only create children once per node
        diagram.model.setDataProperty(data, "everExpanded", true);
        var numchildren = createSubTree(data);
        if (numchildren === 0) {  // now known no children: don't need Button!
          node.findObject('TREEBUTTON').visible = false;
        }
      }
      // this behavior is generic for most expand/collapse tree buttons:
      if (node.isTreeExpanded) {
        diagram.commandHandler.collapseTree(node);
      } else {
        diagram.commandHandler.expandTree(node);
      }
      diagram.commitTransaction("CollapseExpandTree");
    }

    // This dynamically creates the immediate children for a node.
    // The sample assumes that we have no idea of whether there are any children
    // for a node until we look for them the first time, which happens
    // upon the first tree-expand of a node.
    function createSubTree(parentdata) {
      var numchildren = Math.floor(Math.random() * 10);
      if (myDiagram.nodes.count <= 1) {
        numchildren += 1;  // make sure the root node has at least one child
      }
      // create several node data objects and add them to the model
      var model = myDiagram.model;
      var parent = myDiagram.findNodeForData(parentdata);

      var degrees = 1;
      var grandparent = parent.findTreeParentNode();
      while (grandparent) {
        degrees++;
        grandparent = grandparent.findTreeParentNode();
      }

      for (var i = 0; i < numchildren; i++) {
        var childdata = {
          key: model.nodeDataArray.length,
          parent: parentdata.key,
          rootdistance: degrees
        };
        // add to model.nodeDataArray and create a Node
        model.addNodeData(childdata);
        // position the new child node close to the parent
        var child = myDiagram.findNodeForData(childdata);
        child.location = parent.location;
      }
      return numchildren;
    }

    function expandAtRandom() {
      var eligibleNodes = [];
      myDiagram.nodes.each(function(n) {
        if (!n.isTreeExpanded) eligibleNodes.push(n);
      })
      var node = eligibleNodes[Math.floor(Math.random() * (eligibleNodes.length))];
      expandNode(node);
    }
  </script>
</head>
<body onload="init()">
<div id="sample">
  <div id="myDiagramDiv" style="border: solid 1px black; width:100%; height:600px"></div>
  <div id="myOverviewDiv" style="border: solid 1px black; width: 250px; height: 200px"></div>
  <p><button id="zoomToFit">Zoom to Fit</button><button id="expandAtRandom">Expand random Node</button></p>
  <p>
    This sample demonstrates a custom <a>ResizingTool</a> which allows the user to resize the overview box.
    It is defined in its own file, as <a href="OverviewResizingTool.ts">OverviewResizingTool.ts</a>.
  </p>
</div>
</body>
</html>